“…How to harvest microalgae cells is dependent on the characteristics of the microalgae, such as size and density (Olaizola 2003). All of the available harvest approaches, which include flocculation, flotation, centrifugal sedimentation, and filtration, have limitations for effective, cost-efficient production of biofuel (Shelef, Sukenik et al 1984). For instance, flotation methods, based on the trapping of algae cells using dispersed micro-air bubbles, is www.intechopen.com very limited in its technical and economic viability.…”